Bioactive DNA from extracellular vesicles and particles

Extracellular Vesicle Preparation and Analysis: A State-of-the-Art Review

In recent decades, research on Extracellular Vesicles (EVs) has gained prominence in the life sciences due to their critical roles in both health and disease states, offering promising applications in disease diagnosis, drug delivery, and therapy. However, their inherent heterogeneity and complex origins pose significant challenges to their preparation, analysis, and subsequent clinical application. This review is structured to provide an overview of the biogenesis, composition, and various sources of EVs, thereby laying the groundwork for a detailed discussion of contemporary techniques for their preparation and analysis. Particular focus is given to state-of-the-art technologies that employ both microfluidic and non-microfluidic platforms for EV processing. Furthermore, this discourse extends into innovative approaches that incorporate artificial intelligence and cutting-edge electrochemical sensors, with a particular emphasis on single EV analysis. This review proposes current challenges and outlines prospective avenues for future research. The objective is to motivate researchers to innovate and expand methods for the preparation and analysis of EVs, fully unlocking their biomedical potential.

Intercellular transfer of plasmid DNA between in vitro cultured HEK293 cells following transient transfection

Gene overexpression by transient transfection of in vitro cultured model cell lines with plasmid DNA is a commonly used method for studying molecular aspects of human biology and pathobiology. However, there is accumulating evidence suggesting that human cells may actively secrete fragments of DNA and the implications of this phenomenon for in vitro cultured cells transiently transfected with foreign nucleic acids has been overlooked. Therefore, in the current study we investigated whether a cell-to-cell transmission of acquired plasmid DNA takes place in a commonly used human cell line model. We transiently transfected HEK293 cells with EGFP encoding plasmids to serve as donor cells and either co-cultured these with stably mCherry expressing recipient cells in different set-ups or transferred their culture medium to the recipient cells. We found that recipient cells produced EGFP after being co-cultured with donor cells but not when they were exposed to their culture medium. The employment of different co-culture set-ups excluded that the observed effect stemmed from technical artefacts and provided evidence that an intercellular plasmid transfer takes place requiring physical proximity between living cells. This phenomenon could represent a significant biological artefact for certain studies such as those addressing protein transmissions in prion diseases.

Fluorescent, phosphorescent, magnetic resonance contrast and radioactive tracer labelling of extracellular vesicles

This review focusses on the significance of fluorescent, phosphorescent labelling and tracking of extracellular vesicles (EVs) for unravelling their biology, pathophysiology, and potential diagnostic and therapeutic uses. Various labeling strategies, such as lipid membrane, surface protein, luminal, nucleic acid, radionuclide, quantum dot labels, and metal complex-based stains, are evaluated for visualizing and characterizing EVs. Direct labelling with fluorescent lipophilic dyes is simple but generally lacks specificity, while surface protein labelling offers selectivity but may affect EV-cell interactions. Luminal and nucleic acid labelling strategies have their own advantages and challenges. Each labelling approach has strengths and weaknesses, which require a suitable probe and technique based on research goals, but new tetranuclear polypyridylruthenium(II) complexes as phosphorescent probes have strong phosphorescence, selective staining, and stability. Future research should prioritize the design of novel fluorescent probes and labelling platforms that can significantly enhance the efficiency, accuracy, and specificity of EV labeling, while preserving their composition and functionality. It is crucial to reduce false positive signals and explore the potential of multimodal imaging techniques to gain comprehensive insights into EVs.

Neutrophil microRNAs

Neutrophils are considered 'first-line defence' cells as they can be rapidly recruited to the site of the immune response. As key components of non-specific immune mechanisms, neutrophils use phagocytosis, degranulation, and formation of neutrophil extracellular traps (NETs) to fight pathogens. Recently, immunoregulatory abilities of neutrophils associated with the secretion of several mediators, including cytokines and extracellular vesicles (EVs) containing, among other components, microRNAs (miRNAs), have also been reported. EVs are small structures released by cells into the extracellular space and are present in all body fluids. Microvesicles show the composition and status of the releasing cell, its physiological state, and pathological changes. Currently, EVs have gained immense scientific interest as they act as transporters of epigenetic information in intercellular communication. This review summarises findings from recent scientific reports that have evaluated the utility of miRNA molecules as biomarkers for effective diagnostics or even as start-points for new therapeutic strategies in neutrophil-mediated immune reactions. In addition, this review describes the current state of knowledge on miRNA molecules, which are endogenous regulators of gene expression besides being involved in the regulation of the immune response.

Proteomics profiling of extracellular vesicle for identification of potential biomarkers in Alzheimer's disease: A comprehensive review

The intricate origins and diverse symptoms of Alzheimer's disease (AD) pose significant challenges for both diagnosis and treatment. Exosomes and microvesicles, which carry disease-specific cargo from a variety of central nervous system cell types, have emerged as promising reservoirs of biomarkers for AD. Research on the screening of possible biomarkers in Alzheimer's disease using proteomic profiling of EVs is systematically reviewed in this comprehensive review. We highlight key methodologies employed in EV isolation, characterization, and proteomic analysis, elucidating their advantages and limitations. Furthermore, we summarize the evolving landscape of EV-associated biomarkers implicated in AD pathogenesis, including proteins involved in amyloid-beta metabolism, tau phosphorylation, neuroinflammation, synaptic dysfunction, and neuronal injury. The literature review highlights the necessity for robust validation strategies and standardized protocols to effectively transition EV-based biomarkers into clinical use. In the concluding section, this review delves into potential future avenues and technological advancements pivotal in crafting EV-derived biomarkers applicable to AD diagnostics and prognostics. This review contributes to our comprehension of AD pathology and the advancement of precision medicine in neurodegenerative diseases, hinting at a promising era in AD precision medicine.

DAMP sensing and sterile inflammation: intracellular, intercellular and inter-organ pathways

Damage-associated molecular patterns (DAMPs) are endogenous molecules that are released from host cells as a result of cell death or damage. The release of DAMPs in tissues is associated with loss of tissue homeostasis. Sensing of DAMPs by innate immune receptors triggers inflammation, which can be beneficial in initiating the processes that restore tissue homeostasis but can also drive inflammatory diseases. In recent years, the sensing of intracellular DAMPs has received extensive attention in the field of sterile inflammation. However, emerging studies have shown that DAMPs that originate from neighbouring cells, and even from distal tissues or organs, also mediate sterile inflammatory responses. This multi-level sensing of DAMPs is crucial for intercellular, trans-tissue and trans-organ communication. Here, we summarize how DAMP-sensing receptors detect DAMPs from intracellular, intercellular or distal tissue and organ sources to mediate sterile inflammation. We also discuss the possibility of targeting DAMPs or their corresponding receptors to treat inflammatory diseases.

Transforming the Niche: The Emerging Role of Extracellular Vesicles in Acute Myeloid Leukaemia Progression

Acute myeloid leukaemia (AML) management remains a significant challenge in oncology due to its low survival rates and high post-treatment relapse rates, mainly attributed to treatment-resistant leukaemic stem cells (LSCs) residing in bone marrow (BM) niches. This review offers an in-depth analysis of AML progression, highlighting the pivotal role of extracellular vesicles (EVs) in the dynamic remodelling of BM niche intercellular communication. We explore recent advancements elucidating the mechanisms through which EVs facilitate complex crosstalk, effectively promoting AML hallmarks and drug resistance. Adopting a temporal view, we chart the evolving landscape of EV-mediated interactions within the AML niche, underscoring the transformative potential of these insights for therapeutic intervention. Furthermore, the review discusses the emerging understanding of endothelial cell subsets' impact across BM niches in shaping AML disease progression, adding another layer of complexity to the disease progression and treatment resistance. We highlight the potential of cutting-edge methodologies, such as organ-on-chip (OoC) and single-EV analysis technologies, to provide unprecedented insights into AML-niche interactions in a human setting. Leveraging accumulated insights into AML EV signalling to reconfigure BM niches and pioneer novel approaches to decipher the EV signalling networks that fuel AML within the human context could revolutionise the development of niche-targeted therapy for leukaemia eradication.

The acid sphingomyelinase inhibitor imipramine enhances the release of UV photoproduct-containing DNA in small extracellular vesicles in UVB-irradiated human skin

Nucleic acids, lipids, and other cell components can be found within different types of extracellular vesicles (EVs), which include apoptotic bodies (ABs), large extracellular vesicles (LEVs), and small extracellular vesicles (SEVs). Release of LEVs from cells can be reduced by genetic or pharmacological inhibition of the enzyme acid sphinogomyelinase (aSMase), and indeed several studies have demonstrated a role for the clinically approved aSMase inhibitor imipramine in blocking LEV release, including in response to UVB exposure. Given that exposure of keratinocytes to UVB radiation results in the generation of UVR photoproducts in DNA that can subsequently be found in association with ABs and SEVs, we examined how imipramine impacts the release of extracellular DNA containing UVR photoproducts at an early time point after UVR exposure. Using several different model systems, including cultured keratinocytes in vitro, discarded human surgical skin ex vivo, and skin biopsies obtained from treated human subjects, these pilot studies suggest that imipramine treatment stimulates the release of CPD-containing, SEV-associated DNA. These surprising findings indicate that LEV and SEV generation pathways could be linked in UVB-irradiated cells and that imipramine may exacerbate the systemic effects of extracellular UVR-damaged DNA throughout the body.

Cilia Provide a Platform for the Generation, Regulated Secretion, and Reception of Peptidergic Signals

Cilia are microtubule-based cellular projections that act as motile, sensory, and secretory organelles. These structures receive information from the environment and transmit downstream signals to the cell body. Cilia also release vesicular ectosomes that bud from the ciliary membrane and carry an array of bioactive enzymes and peptide products. Peptidergic signals represent an ancient mode of intercellular communication, and in metazoans are involved in the maintenance of cellular homeostasis and various other physiological processes and responses. Numerous peptide receptors, subtilisin-like proteases, the peptide-amidating enzyme, and bioactive amidated peptide products have been localized to these organelles. In this review, we detail how cilia serve as specialized signaling organelles and act as a platform for the regulated processing and secretion of peptidergic signals. We especially focus on the processing and trafficking pathways by which a peptide precursor from the green alga Chlamydomonas reinhardtii is converted into an amidated bioactive product-a chemotactic modulator-and released from cilia in ectosomes. Biochemical dissection of this complex ciliary secretory pathway provides a paradigm for understanding cilia-based peptidergic signaling in mammals and other eukaryotes.

Providing an in vitro depiction of microglial cells challenged with immunostimulatory extracellular vesicles of Naegleria fowleri

Naegleria fowleri is the causative agent of primary amoebic meningoencephalitis, a rapid and acute infection of the central nervous system with a fatal outcome in >97% of cases. Due to the infrequent report of cases and diagnostic gaps that hinder the possibility of recovering clinic isolates, studies related to pathogenesis of the disease are scarce. However, the secretion of cytolytic molecules has been proposed as a factor involved in the progression of the infection. Several of these molecules could be included in extracellular vesicles (EVs), making them potential virulence factors and even modulators of the immune response in this infection. In this work, we evaluated the immunomodulatory effect of EVs secreted by two clinic isolates of Naegleria fowleri using in vitro models. For this purpose, characterization analyses between EVs produced by both isolates were first performed, for subsequent gene transcription analyses post incubation of these vesicles with primary cultures from mouse cell microglia and BV-2 cells. Analyses of morphological changes induced in primary culture microglia cells by the vesicles were also included, as well as the determination of the presence of nucleic acids of N. fowleri in the EV fractions. Results revealed increased expression of NOS, proinflammatory cytokines IL-6, TNF-α, and IL-23, and the regulatory cytokine IL-10 in primary cultures of microglia, as well as increased expression of NOS and IL-13 in BV-2 cells. Morphologic changes from homeostatic microglia, with small cellular body and long processes to a more amoeboid morphology were also observed after the incubation of these cells with EVs. Regarding the presence of nucleic acids, specific Naegleria fowleri DNA that could be amplified using both conventional and qPCR was confirmed in the EV fractions. Altogether, these results confirm the immunomodulatory effects of EVs of Naegleria fowleri over microglial cells and suggest a potential role of these vesicles as biomarkers of primary acute meningoencephalitis.

Molecular profiling in the management of hepatocellular carcinoma

PURPOSE OF REVIEW

The purpose of this review is to both summarize the current knowledge of hepatocellular carcinoma molecular biology and to suggest a framework in which to prospectively translate this knowledge into patient care. This is timely as recent guidelines recommend increased use of these technologies to advance personalized liver cancer care.

RECENT FINDINGS

The main themes covered here address germline and somatic genetic alterations recently discovered in hepatocellular carcinoma, largely owing to next generation sequencing technologies, and nascent efforts to translate these into contemporary practice.

SUMMARY

Early efforts of translating molecular profiling to hepatocellular carcinoma care demonstrate a growing number of potentially actionable alterations. Still lacking are a consensus on what biomarkers and technologies to adopt, at what scale and cost, and how to integrate them most effectively into care.

Profiling DNA Cargos in Single Extracellular Vesicles via Hydrogel-Based Droplet Digital Multiple Displacement Amplification

Due to the substantial heterogeneity among extracellular vesicle (EV) subpopulations, single-EV analysis has the potential to elucidate the mechanisms behind EV biogenesis and shed light on the myriad functions, leading to the development of novel diagnostics and therapeutics. While many studies have been devoted to reveal between-EV variations in surface proteins and RNAs, DNA cargos (EV-DNA) have received little attention. Here, we report a hydrogel-based droplet digital multiple displacement amplification approach for the comprehensive analysis of EV-DNA at the single-EV level. Single EVs are dispersed in thousands of hydrogel droplets and lysed for DNA amplification and identification. The droplet microfluidics strategy empowers the assay with single-molecule sensitivity and capability for absolute quantification of DNA-containing EVs. In particular, our findings indicate that 5-40% EVs are associated with DNA, depending on the cell of origin. Large EVs exhibit a higher proportion of DNA-containing EVs and a more substantial presence of intraluminal DNA, compared to small EVs. These DNA-containing EVs carry multiple DNA fragments on average. Furthermore, both double-stranded DNA and single-stranded DNA were able to be detected at the single-EV level. Utilizing this method, the abundance, distribution, and biophysical properties of EV-DNA in various EV populations are evaluated. The DNA level within EVs provides insight into the status of the originating cells and offers valuable information on the outcomes of anticancer treatments. The utilization of single-EV analysis for EV-DNA holds significant promise for early cancer detection and treatment response monitoring.

Impact of platelet activation on the release of cell-free mitochondria and circulating mitochondrial DNA

BACKGROUND

Research on circulating mitochondrial DNA (cir-mtDNA) based diagnostic is insufficient, as to its function, origin, structural features, and particularly its standardization of isolation. To date, plasma preparation performed in previous studies do not take into consideration the potential bias resulting from the release of mitochondria by activated platelets.

METHODS

To tackle this, we compared the mtDNA amount determined by a standard plasma preparation method or a method optimally avoiding platelet activation. MtDNA extracted from the plasma of seven healthy individuals was quantified by Q-PCR in the course of the process of both methods submitted to filtration, freezing or differential centrifugation.

RESULTS

98.7 to 99.4% of plasma mtDNA corresponded to extracellular mitochondria, either free or into large extracellular vesicles. Without platelet activation, the proportion of both types of entities remained preponderant (76-80%), but the amount of detected mtDNA decreased 67-fold.

CONCLUSION

We show the high capacity of platelets to release free mitochondria in "in vitro" conditions. This represents a potent confounding factor when extracting mtDNA for cir-mtDNA investigation. Platelet activation during pre-analytical conditions should therefore be avoided when studying cir-mtDNA. Our findings lead to a profound revision of the assumptions previously made by most works in this field. Overall, our data suggest the need to characterize or isolate mtDNA associated various structural forms, as well as to standardize plasma preparation, to better circumscribe cir-mtDNA's diagnostic capacity.

Platelet-Derived Apoptotic Vesicles Promote Bone Regeneration via Golgi Phosphoprotein 2 (GOLPH2)-AKT Signaling Axis

Apoptotic vesicles (apoVs) are apoptotic-cell-derived nanosized vesicles that take on dominant roles in regulating bone homeostasis. We have demonstrated that mesenchymal stem cell (MSC)-derived apoVs are promising therapeutic agents for bone regeneration. However, clinical translation of MSC-derived apoVs has been hindered due to cell expansion and nuclear substance. As another appealing source for apoV therapy, blood cells could potentially eliminate these limitations. However, whether blood cells can release apoVs during apoptosis is uncertain, and the detailed characteristics and biological properties of respective apoVs are not elucidated. In this study, we showed that platelets (PLTs) could rapidly release abundant apoVs during apoptosis in a short time. To recognize the different protein expressions between PLT-derived apoVs and PLTs, we established their precise protein landscape. Furthermore, we identified six proteins specifically enriched in PLT-derived apoVs, which could be considered as specific biomarkers. More importantly, PLT-derived apoVs promoted osteogenesis of MSCs and rescued bone loss via Golgi phosphoprotein 2 (GOLPH2)-induced AKT phosphorylation, therefore, leading to the emergence of their potential in bone regeneration. In summary, we comprehensively determined characteristics of PLT-derived apoVs and confirmed their roles in bone metabolism through previously unrecognized GOPLH2-dependent AKT signaling, providing more understanding for exploring apoV-based therapy in bone tissue engineering.

Glycosylation in extracellular vesicles: Isolation, characterization, composition, analysis and clinical applications

This review provides a comprehensive overview of our understanding of the role that glycans play in the formation, loading and release of extracellular vesicles (EVs). The capture of EVs (typically with a size of 100-200 nm) is described, including approaches based on glycan recognition with glycan-based analysis offering highly sensitive detection of EVs. Furthermore, detailed information is provided about the use of EV glycans and glycan processing enzymes as potential biomarkers, therapeutic targets or tools applied for regenerative medicine. The review also provides a short introduction into advanced methods for the characterization of EVs, new insights into the biomolecular corona covering EVs and bioanalytical tools available for glycan analysis.

Characterization of the extracellular vesicles, ultrastructural morphology, and intercellular interactions of multiple clinical isolates of the brain-eating amoeba, Naegleria fowleri

Introduction

As global temperatures rise to unprecedented historic levels, so too do the latitudes of habitable niches for the pathogenic free-living amoeba, Naegleria fowleri. This opportunistic parasite causes a rare, but >97% fatal, neurological infection called primary amoebic meningoencephalitis. Despite its lethality, this parasite remains one of the most neglected and understudied parasitic protozoans.

Methods

To better understand amoeboid intercellular communication, we elucidate the structure, proteome, and potential secretion mechanisms of amoeba-derived extracellular vesicles (EVs), which are membrane-bound communication apparatuses that relay messages and can be used as biomarkers for diagnostics in various diseases.

Results and Discussion

Herein we propose that N. fowleri secretes EVs in clusters from the plasma membrane, from multivesicular bodies, and via beading of thin filaments extruding from the membrane. Uptake assays demonstrate that EVs are taken up by other amoebae and mammalian cells, and we observed a real-time increase in metabolic activity for mammalian cells exposed to EVs from amoebae. Proteomic analysis revealed >2,000 proteins within the N. fowleri-secreted EVs, providing targets for the development of diagnostics or therapeutics. Our work expands the knowledge of intercellular interactions among these amoebae and subsequently deepens the understanding of the mechanistic basis of PAM.

Monitoring of single extracellular vesicle heterogeneity in cancer progression and therapy

Cancer cells actively release lipid bilayer extracellular vesicles (EVs) that affect their microenvironment, favoring their progression and response to extracellular stress. These EVs contain dynamically regulating molecular cargos (proteins and nucleic acids) selected from their parental cells, representing the active biological functionality for cancer progression. These EVs are heterogeneous according to their size and molecular composition and are usually defined based on their biogenetic mechanisms, such as exosomes and ectosomes. Recent single EV detection technologies, such as nano-flow cytometry, have revealed the dynamically regulated molecular diversity within bulk EVs, indicating complex EV heterogeneity beyond classical biogenetic-based EV subtypes. EVs can be changed by internal oncogenic transformation or external stress such as chemotherapy. Among the altered combinations of EV subtypes, only a specific set of EVs represents functional molecular cargo, enabling cancer progression and immune modulation in the tumor microenvironment through their altered targeting efficiency and specificity. This review covers the heterogeneity of EVs discovered by emerging single EV analysis technologies, which reveal the complex distribution of EVs affected by oncogenic transformation and chemotherapy. Encouragingly, these unique molecular signatures in individual EVs indicate the status of their parental cancer cells. Thus, precise molecular profiling of circulating single EVs would open new areas for in-depth monitoring of the cancer microenvironment and shed new light on non-invasive diagnostic approaches using liquid biopsy.

A Novel Dual-Reporter System Reveals Distinct Characteristics of Exosome-Mediated Protein Secretion in Human Cells

BACKGROUND

Exosomes, a special subtype of extracellular vesicles derived from human cells, serve as vital mediators of intercellular communication by transporting diverse bioactive cargos, including proteins and enzymes. However, the underlying mechanisms governing exosome secretion and regulation remain poorly understood. In this study, we employed a dual-reporter system consisting of bioluminescent Gaussia luciferase and fluorescent proteins to investigate the dynamics and regulation of exosome secretion in cultured human cells.

RESULTS

Our results demonstrated that the engineered dual-reporters effectively monitored both exosome-mediated and ER-Golgi-mediated secretory pathways in a specific and quantitative manner. Notably, we observed distinct characteristics of exosome-mediated protein secretion, including significantly lower capacity and different dynamics compared to the ER-Golgi pathway. This phenomenon was observed in human kidney 293T cells and liver HepG2 cells, emphasizing the conserved nature of exosome-mediated secretion across cell types. Furthermore, we investigated the impact of brefeldin A (BFA), an inhibitor of ER-to-Golgi membrane trafficking, on protein secretion. Interestingly, BFA inhibited protein secretion via the ER-Golgi pathway while stimulating exosome-mediated protein secretion under same experimental conditions.

CONCLUSIONS

Collectively, our study highlights the utility of the dual-reporter system for real-time monitoring and quantitative analysis of protein secretion through conventional ER-Golgi and unconventional exosome pathways. Moreover, our findings unveil distinct features of exosome-mediated protein secretion, shedding light on its differential capacity, dynamics, and regulatory mechanisms compared to ER-Golgi-mediated proteins in human cells.

The Diagnostic, Prognostic, and Therapeutic Potential of Cell-Free DNA with a Special Focus on COVID-19 and Other Viral Infections

Cell-free DNA (cfDNA) in human blood serum, urine, and other body fluids recently became a commonly used diagnostic marker associated with various pathologies. This is because cfDNA enables a much higher sensitivity than standard biochemical parameters. The presence of and/or increased level of cfDNA has been reported for various diseases, including viral infections, including COVID-19. Here, we review cfDNA in general, how it has been identified, where it can derive from, its molecular features, and mechanisms of release and clearance. General suitability of cfDNA for diagnostic questions, possible shortcomings and future directions are discussed, with a special focus on coronavirus infection.

Challenges and Prospects of Patient-Derived Xenografts for Cancer Research

We discuss the importance of the in vivo models in elucidating cancer biology, focusing on the patient-derived xenograft (PDX) models, which are classic and standard functional in vivo platforms for preclinical evaluation. We provide an overview of the most representative models, including cell-derived xenografts (CDX), tumor and metastatic cell-derived xenografts, and PDX models utilizing humanized mice (HM). The orthotopic models, which could reproduce the cancer environment and its progression, similar to human tumors, are particularly common. The standard procedures and rationales of gastric adenocarcinoma (GAC) orthotopic models are addressed. Despite the significant advantages of the PDX models, such as recapitulating key features of human tumors and enabling drug testing in the in vivo context, some challenges must be acknowledged, including loss of heterogeneity, selection bias, clonal evolution, stroma replacement, tumor micro-environment (TME) changes, host cell carryover and contaminations, human-to-host cell oncogenic transformation, human and host viral infections, as well as limitations for immunologic research. To compensate for these limitations, other mouse models, such as syngeneic and humanized mouse models, are currently utilized. Overall, the PDX models represent a powerful tool in cancer research, providing critical insights into tumor biology and potential therapeutic targets, but their limitations and challenges must be carefully considered for their effective use. Lastly, we present an intronic quantitative PCR (qPCR) method to authenticate, detect, and quantify human/murine cells in cell lines and PDX samples.

Isolation of Extracellular Vesicles of Holothuria (Sea Cucumber Eupentacta fraudatrix)

Extracellular vesicles (EVs), carriers of molecular signals, are considered a critical link in maintaining homeostasis in mammals. Currently, there is growing interest in studying the role of EVs, including exosomes (subpopulation of EVs), in animals of other evolutionary levels, including marine invertebrates. We have studied the possibility of obtaining appropriate preparations of EVs from whole-body extract of holothuria Eupentacta fraudatrix using a standard combination of centrifugation and ultracentrifugation. However, the preparations were heavily polluted, which did not allow us to conclude that they contained vesicles. Subsequent purification by FLX gel filtration significantly reduced the pollution but did not increase vesicle concentration to a necessary level. To detect EVs presence in the body of holothurians, we used transmission electron microscopy of ultrathin sections. Late endosomes, producing the exosomes, were found in the cells of the coelom epithelium covering the gonad, digestive tube and respiratory tree, as well as in the parenchyma cells of these organs. The study of purified homogenates of these organs revealed vesicles (30-100 nm) morphologically corresponding to exosomes. Thus, we can say for sure that holothurian cells produce EVs including exosomes, which can be isolated from homogenates of visceral organs.

The Polyanionic Drug Suramin Neutralizes Histones and Prevents Endotheliopathy

Drugs are needed to protect against the neutrophil-derived histones responsible for endothelial injury in acute inflammatory conditions such as trauma and sepsis. Heparin and other polyanions can neutralize histones but challenges with dosing or side effects such as bleeding limit clinical application. In this study, we demonstrate that suramin, a widely available polyanionic drug, completely neutralizes the toxic effects of individual histones, but not citrullinated histones from neutrophil extracellular traps. The sulfate groups on suramin form stable electrostatic interactions with hydrogen bonds in the histone octamer with a dissociation constant of 250 nM. In cultured endothelial cells (Ea.Hy926), histone-induced thrombin generation was significantly decreased by suramin. In isolated murine blood vessels, suramin abolished aberrant endothelial cell calcium signals and rescued impaired endothelial-dependent vasodilation caused by histones. Suramin significantly decreased pulmonary endothelial cell ICAM-1 expression and neutrophil recruitment caused by infusion of sublethal doses of histones in vivo. Suramin also prevented histone-induced lung endothelial cell cytotoxicity in vitro and lung edema, intra-alveolar hemorrhage, and mortality in mice receiving a lethal dose of histones. Protection of vascular endothelial function from histone-induced damage is a novel mechanism of action for suramin with therapeutic implications for conditions characterized by elevated histone levels.

Tumor-derived nanoseeds condition the soil for metastatic organotropism

Primary tumors secrete a variety of factors to turn distant microenvironments into favorable and fertile 'soil' for subsequent metastases. Among these 'seeding' factors that initiate pre-metastatic niche (PMN) formation, tumor-derived extracellular vesicles (EVs) are of particular interest as tumor EVs can direct organotropism depending on their surface integrin profiles. In addition, EVs also contain versatile, bioactive cargo, which include proteins, metabolites, lipids, RNA, and DNA fragments. The cargo incorporated into EVs is collectively shed from cancer cells and cancer-associated stromal cells. Increased understanding of how tumor EVs promote PMN establishment and detection of EVs in bodily fluids highlight how tumor EVs could serve as potential diagnostic and prognostic biomarkers, as well as provide a therapeutic target for metastasis prevention. This review focuses on tumor-derived EVs and how they direct organotropism and subsequently modulate stromal and immune microenvironments at distal sites to facilitate PMN formation. We also outline the progress made thus far towards clinical applications of tumor EVs.

Extracellular vesicles: Focus on peri-implantation period of pregnancy in pigs

The establishment of cell-to-cell communication between the endometrium and the developing embryo is the most important step in successful mammalian pregnancy. Close interaction between the uterine luminal epithelium and trophoblast cells requires triggering timely molecular dialog for successful maternal recognition of pregnancy, embryo implantation, and placenta development. Quite recently, extracellular vesicles (EVs) carrying unique molecular cargo emerged as evolutionarily conserved mediators of cell-to-cell communication during early pregnancy. To date, the presence of EVs at the embryo-maternal interface has been demonstrated in numerous mammals, including domestic livestock, such as pigs. However, few studies have focused on revealing the mechanism of EV-mediated crosstalk between developing early embryos and receptive endometrium. Over the past years, it has appeared that understanding the role of EVs in mammalian reproduction can substantially improve our understanding of the biological challenges of successful reproductive performance. This review describes current knowledge of EVs, specifically in relation to the peri-implantation period in pigs, characterized by common features of embryo implantation and high embryonic mortality in mammals.

Horizontal Transfer of Malignant Traits and the Involvement of Extracellular Vesicles in Metastasis

Metastases are responsible for the vast majority of cancer deaths, yet most therapeutic efforts have focused on targeting and interrupting tumor growth rather than impairing the metastatic process. Traditionally, cancer metastasis is attributed to the dissemination of neoplastic cells from the primary tumor to distant organs through blood and lymphatic circulation. A thorough understanding of the metastatic process is essential to develop new therapeutic strategies that improve cancer survival. Since Paget's original description of the "Seed and Soil" hypothesis over a hundred years ago, alternative theories and new players have been proposed. In particular, the role of extracellular vesicles (EVs) released by cancer cells and their uptake by neighboring cells or at distinct anatomical sites has been explored. Here, we will outline and discuss these alternative theories and emphasize the horizontal transfer of EV-associated biomolecules as a possibly major event leading to cell transformation and the induction of metastases. We will also highlight the recently discovered intracellular pathway used by EVs to deliver their cargoes into the nucleus of recipient cells, which is a potential target for novel anti-metastatic strategies.

Extracellular Vesicles and Epidermal Growth Factor Receptor Activation: Interplay of Drivers in Cancer Progression

Extracellular vesicles (EVs) are of great interest to study the cellular mechanisms of cancer development and to diagnose and monitor cancer progression. EVs are a highly heterogeneous population of cell derived particles, which include microvesicles (MVs) and exosomes (EXOs). EVs deliver intercellular messages transferring proteins, lipids, nucleic acids, and metabolites with implications for tumour progression, invasiveness, and metastasis. Epidermal Growth Factor Receptor (EGFR) is a major driver of cancer. Tumour cells with activated EGFR could produce EVs disseminating EGFR itself or its ligands. This review provides an overview of EVs (mainly EXOs and MVs) and their cargo, with a subsequent focus on their production and effects related to EGFR activation. In particular, in vitro studies performed in EGFR-dependent solid tumours and/or cell cultures will be explored, thus shedding light on the interplay between EGFR and EVs production in promoting cancer progression, metastases, and resistance to therapies. Finally, an overview of liquid biopsy approaches involving EGFR and EVs in the blood/plasma of EGFR-dependent tumour patients will also be discussed to evaluate their possible application as candidate biomarkers.

Exploiting the biogenesis of extracellular vesicles for bioengineering and therapeutic cargo loading

Extracellular vesicles (EVs) are gaining increasing attention for diagnostic and therapeutic applications in various diseases. These natural nanoparticles benefit from favorable safety profiles and unique biodistribution capabilities, rendering them attractive drug-delivery modalities over synthetic analogs. However, the widespread use of EVs is limited by technological shortcomings and biological knowledge gaps that fail to unravel their heterogeneity. An in-depth understanding of their biogenesis is crucial to unlocking their full therapeutic potential. Here, we explore how knowledge about EV biogenesis can be exploited for EV bioengineering to load therapeutic protein or nucleic acid cargos into or onto EVs. We summarize more than 75 articles and discuss their findings on the formation and composition of exosomes and microvesicles, revealing multiple pathways that may be stimulation and/or cargo dependent. Our analysis further identifies key regulators of natural EV cargo loading and we discuss how this knowledge is integrated to develop engineered EV biotherapeutics.

Exosomes: Nomenclature, Isolation, and Biological Roles in Liver Diseases

The biogenesis and biological roles of extracellular vesicles (EVs) in the progression of liver diseases have attracted considerable attention in recent years. EVs are membrane-bound nanosized vesicles found in different types of body fluids and contain various bioactive materials, including proteins, lipids, nucleic acids, and mitochondrial DNA. Based on their origin and biogenesis, EVs can be classified as apoptotic bodies, microvesicles, and exosomes. Among these, exosomes are the smallest EVs (30-150 nm in diameter), which play a significant role in cell-to-cell communication and epigenetic regulation. Moreover, exosomal content analysis can reveal the functional state of the parental cell. Therefore, exosomes can be applied to various purposes, including disease diagnosis and treatment, drug delivery, cell-free vaccines, and regenerative medicine. However, exosome-related research faces two major limitations: isolation of exosomes with high yield and purity and distinction of exosomes from other EVs (especially microvesicles). No standardized exosome isolation method has been established to date; however, various exosome isolation strategies have been proposed to investigate their biological roles. Exosome-mediated intercellular communications are known to be involved in alcoholic liver disease and nonalcoholic fatty liver disease development. Damaged hepatocytes or nonparenchymal cells release large numbers of exosomes that promote the progression of inflammation and fibrogenesis through interactions with neighboring cells. Exosomes are expected to provide insight on the progression of liver disease. Here, we review the biogenesis of exosomes, exosome isolation techniques, and biological roles of exosomes in alcoholic liver disease and nonalcoholic fatty liver disease.

Methods to Evaluate Changes in Mitochondrial Structure and Function in Cancer

Mitochondria are regulators of key cellular processes, including energy production and redox homeostasis. Mitochondrial dysfunction is associated with various human diseases, including cancer. Importantly, both structural and functional changes can alter mitochondrial function. Morphologic and quantifiable changes in mitochondria can affect their function and contribute to disease. Structural mitochondrial changes include alterations in cristae morphology, mitochondrial DNA integrity and quantity, and dynamics, such as fission and fusion. Functional parameters related to mitochondrial biology include the production of reactive oxygen species, bioenergetic capacity, calcium retention, and membrane potential. Although these parameters can occur independently of one another, changes in mitochondrial structure and function are often interrelated. Thus, evaluating changes in both mitochondrial structure and function is crucial to understanding the molecular events involved in disease onset and progression. This review focuses on the relationship between alterations in mitochondrial structure and function and cancer, with a particular emphasis on gynecologic malignancies. Selecting methods with tractable parameters may be critical to identifying and targeting mitochondria-related therapeutic options. Methods to measure changes in mitochondrial structure and function, with the associated benefits and limitations, are summarized.

Mutation detection of urinary cell-free DNA via catch-and-release isolation on nanowires for liquid biopsy

Cell-free DNA (cfDNA) and extracellular vesicles (EVs) are molecular biomarkers in liquid biopsies that can be applied for cancer detection, which are known to carry information on the necessary conditions for oncogenesis and cancer cell-specific activities after oncogenesis, respectively. Analyses for both cfDNA and EVs from the same body fluid can provide insights into screening and identifying the molecular subtypes of cancer; however, a major bottleneck is the lack of efficient and standardized techniques for the isolation of cfDNA and EVs from clinical specimens. Here, we achieved catch-and-release isolation by hydrogen bond-mediated binding of cfDNA in urine to zinc oxide (ZnO) nanowires, which also capture EVs by surface charge, and subsequently we identified genetic mutations in urinary cfDNA. The binding strength of hydrogen bonds between single-crystal ZnO nanowires and DNA was found to be equal to or larger than that of conventional hydrophobic interactions, suggesting the possibility of isolating trace amounts of cfDNA. Our results demonstrated that nanowire-based cancer screening assay can screen cancer and can identify the molecular subtypes of cancer in urine from brain tumor patients through EV analysis and cfDNA mutation analysis. We anticipate our method to be a starting point for more sophisticated diagnostic models of cancer screening and identification.

Emerging role of extracellular vesicles in multiple sclerosis: From cellular surrogates to pathogenic mediators and beyond

Multiple Sclerosis (MS) is a chronic, inflammatory demyelinating disease of the central nervous system (CNS) driven by a complex interplay of genetic and environmental factors. While the therapeutic arsenal has expanded significantly for management of relapsing forms of MS, treatment of individuals with progressive MS is suboptimal. This treatment inequality is in part due to an incomplete understanding of pathomechanisms at different stages of the disease-underscoring the critical need for new biomarkers. Extracellular vesicles (EVs) and their bioactive cargo have emerged as endogenous nanoparticles with great theranostic potential-as diagnostic and prognostic biomarkers and ultimately as therapeutic candidates for precision nanotherapeutics. The goals of this review are to: 1) summarize the current data investigating the role of EVs and their bioactive cargo in MS pathogenesis, 2) provide a high level overview of advances and challenges in EV isolation and characterization for translational studies, and 3) conclude with future perspectives on this evolving field.

Moonlighting chromatin: when DNA escapes nuclear control

Extracellular chromatin, for example in the form of neutrophil extracellular traps (NETs), is an important element that propels the pathological progression of a plethora of diseases. DNA drives the interferon system, serves as autoantigen, and forms the extracellular scaffold for proteins of the innate immune system. An insufficient clearance of extruded chromatin after the release of DNA from the nucleus into the extracellular milieu can perform a secret task of moonlighting in immune-inflammatory and occlusive disorders. Here, we discuss (I) the cellular events involved in the extracellular release of chromatin and NET formation, (II) the devastating consequence of a dysregulated NET formation, and (III) the imbalance between NET formation and clearance. We include the role of NET formation in the occlusion of vessels and ducts, in lung disease, in autoimmune diseases, in chronic oral disorders, in cancer, in the formation of adhesions, and in traumatic spinal cord injury. To develop effective therapies, it is of utmost importance to target pathways that cause decondensation of chromatin during exaggerated NET formation and aggregation. Alternatively, therapies that support the clearance of extracellular chromatin are conceivable.

Investigation of the Presence of DNA in Human Blood Plasma Small Extracellular Vesicles

Extracellular DNA (ecDNA) is DNA outside of cells, which is a result of various mechanisms. EcDNA is believed to be a cause of various pathogeneses as well as their potential biomarker. EcDNA is believed to also be part of small extracellular vesicles (sEVs) from cell cultures. If ecDNA is present in sEVs in plasma, their membrane may protect it from degradation by deoxyribonucleases. Moreover, sEVs play a role in the intercellular communication, and they can therefore transfer ecDNA between cells. The aim of this study was to investigate the presence of ecDNA in sEVs isolated from fresh human plasma by the ultracentrifugation and density gradient, which serves to exclude the co-isolation of non-sEVs compartments. The novelty of the current study is the investigation of the localization and subcellular origin of the ecDNA associated with sEVs in plasma, as well as the estimation of the approximate concentration. The cup-shaped sEVs were confirmed by transmission electron microscopy. The highest concentration of particles was in the size of 123 nm. The presence of the sEVs markers CD9 and TSG101 was confirmed by western blot. It was found that 60-75% of DNA is on the surface of sEVs, but a part of the DNA is localized inside the sEVs. Moreover, both nuclear and mitochondrial DNA were present in plasma EVs. Further studies should focus on the potential harmful autoimmune effect of DNA carried by plasma EVs or specifically sEVs.

Advances of multi-omics applications in hepatic precancerous lesions and hepatocellular carcinoma: The role of extracellular vesicles

Due to the lack of distinct early symptoms and specific biomarkers, most patients with hepatocellular carcinoma (HCC) are usually diagnosed at advanced stages, rendering the treatment ineffective and useless. Therefore, recognition of the malady at precancerous lesions and early stages is particularly important for improving patient outcomes. The interest in extracellular vesicles (EVs) has been growing in recent years with the accumulating knowledge of their multiple cargoes and related multipotent roles in the modulation of immune response and tumor progression. By virtue of the rapid advancement of high-throughput techniques, multiple omics, including genomics/transcriptomics, proteomics, and metabolomics/lipidomics, have been widely integrated to analyze the role of EVs. Comprehensive analysis of multi-omics data will provide useful insights for discovery of new biomarkers and identification of therapeutic targets. Here, we review the attainment of multi-omics analysis to the finding of the potential role of EVs in early diagnosis and the immunotherapy in HCC.

Mature Red Blood Cells Contain Long DNA Fragments and Could Acquire DNA from Lung Cancer Tissue

Red blood cells (RBC) are commonly known as cells with no nucleus or mitochondria and are assumed to be a transportation vehicle. This study confirms that RBC contain long DNA fragments inside with stain by both microscope and flow cytometry, which covers most nuclear and mitochondrial genome regions by next-generation sequencing (NGS). Such characteristics demonstrate a significant difference compared with A549 cell line or paired peripheral blood mononuclear cell as nucleated cells. To further explore the characteristics of RNA DNA, DNA from 20 RBC samples is sequenced by NGS. Interestingly, several gaps and multiple regions with copy number variation are observed significantly different between different samples, which could be used to distinguish samples with different health status accurately. Using an in vitro co-culture system, it is shown that RBC could absorb DNA-bearing tumorigenic mutations from cancer cell lines but requires cell-to-cell contact. Finally, based on a small scale clinical trial, it is confirmed that common genetic mutations of cancer tissues could be detected in RBC from patients with early-stage non-small-cell lung cancer. This study highlights a new biological phenomenon involving RBC and its translational potential as a novel liquid biopsy technology platform for early cancer screening and diagnosis of malignancy.

From Conventional to Microfluidic: Progress in Extracellular Vesicle Separation and Individual Characterization

Extracellular vesicles (EVs) are nanoscale membrane vesicles, which contain a wide variety of cargo such as proteins, miRNAs, and lipids. A growing body of evidence suggests that EVs are promising biomarkers for disease diagnosis and therapeutic strategies. Although the excellent clinical value, their use in personalized healthcare practice is not yet feasible due to their highly heterogeneous nature. Taking the difficulty of isolation and the small size of EVs into account, the characterization of EVs at a single-particle level is both imperative and challenging. In a bid to address this critical point, more research has been directed into a microfluidic platform because of its inherent advantages in sensitivity, specificity, and throughput. This review discusses the biogenesis and heterogeneity of EVs and takes a broad view of state-of-the-art advances in microfluidics-based EV research, including not only EV separation, but also the single EV characterization of biophysical detection and biochemical analysis. To highlight the advantages of microfluidic techniques, conventional technologies are included for comparison. The current status of artificial intelligence (AI) for single EV characterization is then presented. Furthermore, the challenges and prospects of microfluidics and its combination with AI applications in single EV characterization are also discussed. In the foreseeable future, recent breakthroughs in microfluidic platforms are expected to pave the way for single EV analysis and improve applications for precision medicine.

Extracellular Vesicle-DNA: The Next Liquid Biopsy Biomarker for Early Cancer Diagnosis?

After a short introduction about the history of liquid biopsy, aimed to noninvasively replace the common tissue biopsy as a help for cancer diagnosis, this review is focused on extracellular vesicles (EVs), as the main third component, which is now coming into the light of liquid biopsy. Cell-derived EV release is a recently discovered general cellular property, and EVs harbor many cellular components reflecting their cell of origin. This is also the case for tumoral cells, and their cargoes might therefore be a "treasure chest" for cancer biomarkers. This has been extensively explored for a decade, but the EV-DNA content escaped this worldwide query until recently. The aim of this review is to gather the pilot studies focused on the DNA content of circulating cell-derived EVs, and the following five years of studies about the circulating tumor EV-DNA. The recent preclinical studies about the circulating tEV-derived gDNA as a potential cancer biomarker developed into a puzzling controversy about the presence of DNA into exosomes, coupled with an increased unexpected non vesicular complexity of the extracellular environment. This is discussed in the present review, together with the challenges that need to be solved before any efficient clinical transfer of EV-DNA as a quite promising cancer diagnosis biomarker.

A new intronic quantitative PCR method led to the discovery of transformation from human ascites to murine malignancy in a mouse model

Purpose

To establish a fast and accurate detection method for interspecies contaminations in the patient-derived xenograft (PDX) models and cell lines, and to elucidate possible mechanisms if interspecies oncogenic transformation is detected.

Methods

A fast and highly sensitive intronic qPCR method detecting Gapdh intronic genomic copies was developed to quantify if cells were human or murine or a mixture. By this method, we documented that murine stromal cells were abundant in the PDXs; we also authenticated our cell lines to be human or murine.

Results

In one mouse model, GA0825-PDX transformed murine stromal cells into a malignant tumorigenic murine P0825 cell line. We traced the timeline of this transformation and discovered three subpopulations descended from the same GA0825-PDX model: epithelium-like human H0825, fibroblast-like murine M0825, and main passaged murine P0825 displayed differences in tumorigenic capability in vivo. P0825 was the most aggressive and H0825 was weakly tumorigenic. Immunofluorescence (IF) staining revealed that P0825 cells highly expressed several oncogenic and cancer stem cell markers. Whole exosome sequencing (WES) analysis revealed that TP53 mutation in the human ascites IP116-generated GA0825-PDX may have played a role in the human-to-murine oncogenic transformation.

Conclusion

This intronic qPCR is able to quantify human/mouse genomic copies with high sensitivity and within a time frame of a few hours. We are the first to use intronic genomic qPCR for authentication and quantification of biosamples. Human ascites transformed murine stroma into malignancy in a PDX model.

Lipopolysaccharide Primes Human Macrophages for Noncanonical Inflammasome-Induced Extracellular Vesicle Secretion

Human macrophages secrete extracellular vesicles (EVs) loaded with numerous immunoregulatory proteins. Vesicle-mediated protein secretion in macrophages is regulated by poorly characterized mechanisms; however, it is now known that inflammatory conditions significantly alter both the quantities and protein composition of secreted vesicles. In this study, we employed high-throughput quantitative proteomics to characterize the modulation of EV-mediated protein secretion during noncanonical caspase-4/5 inflammasome activation via LPS transfection. We show that human macrophages activate robust caspase-4-dependent EV secretion upon transfection of LPS, and this process is also partially dependent on NLRP3 and caspase-5. A similar effect occurs with delivery of the LPS with Escherichia coli-derived outer membrane vesicles. Moreover, sensitization of the macrophages through TLR4 by LPS priming prior to LPS transfection dramatically augments the EV-mediated protein secretion. Our data demonstrate that this process differs significantly from canonical inflammasome activator ATP-induced vesiculation, and it is dependent on the autocrine IFN signal associated with TLR4 activation. LPS priming preceding the noncanonical inflammasome activation significantly enhances vesicle-mediated secretion of inflammasome components caspase-1, ASC, and lytic cell death effectors GSDMD, MLKL, and NINJ1, suggesting that inflammatory EV transfer may exert paracrine effects in recipient cells. Moreover, using bioinformatics methods, we identify 15-deoxy-Δ12,14-PGJ2 and parthenolide as inhibitors of caspase-4-mediated inflammation and vesicle secretion, indicating new therapeutic potential of these anti-inflammatory drugs.

Protein and Lipid Content of Milk Extracellular Vesicles: A Comparative Overview

The characterization of the protein and lipid cargo of milk extracellular vesicles from different mammal species is crucial for understanding their biogenesis and biological functions, as well as for a comprehensive description of the nutritional aspects of animal milk for human diet. In fact, milk EVs have been reported to possess relevant biological effects, but the molecules/biochemical pathways underlying these effects have been poorly investigated. The biochemical characterization is an important initial step for the potential therapeutic and diagnostic use of natural or modified milk EVs. The number of studies analysing the protein and lipid composition of milk EVs is limited compared to that investigating the nucleic acid cargo. Here, we revised the literature regarding the protein and lipid content of milk EVs. Until now, most investigations have shown that the biochemical cargo of EVs is different with respect to that of other milk fractions. In addition, even if these studies derived mostly from bovine and human milk EVs, comparison between milk EVs from different animal species and milk EVs biochemical composition changes due to different factors including lactation stages and health status is also beginning to be reported.

Tumor-Derived Extracellular Vesicles: Multifunctional Entities in the Tumor Microenvironment

Tumor cells release extracellular vesicles (EVs) that can function as mediators of intercellular communication in the tumor microenvironment. EVs contain a host of bioactive cargo, including membrane, cytosolic, and nuclear proteins, in addition to noncoding RNAs, other RNA types, and double-stranded DNA fragments. These shed vesicles may deposit paracrine information and can also be taken up by stromal cells, causing the recipient cells to undergo phenotypic changes that profoundly impact diverse facets of cancer progression. For example, this unique form of cellular cross talk helps condition the premetastatic niche, facilitates evasion of the immune response, and promotes invasive and metastatic activity. These findings, coupled with those demonstrating that the number and content of EVs produced by tumors can vary depending on their tumor of origin, disease stage, or response to therapy, have raised the exciting possibility that EVs can be used for risk stratification, diagnostic, and even prognostic purposes. We summarize recent developments and the current knowledge of EV cargoes, their impact on disease progression, and implementation of EV-based liquid biopsies as tumor biomarkers.

The therapeutic and commercial landscape of stem cell vesicles in regenerative dermatology

Extracellular vesicles (EVs) are lipid enveloped nanoparticles that are naturally produced by cells and function in the intercellular transfer of biological material such as proteins, RNAs and metabolites. They have been shown to act in an autocrine and paracrine manner to alter the functions of local and distant recipient cells, with a growing body of evidence highlighting their wide-ranging functions in regenerative processes such as stem cell maintenance, tissue repair and immune modulation. EVs offer several potential advantages over stem cell therapies such as improved safety profiles, scalability, and enhanced storage and quality control of the final product. In fact, many of the pro-regenerative outcomes of stem cell therapies have been attributed to the release of mesenchymal stem cell-derived EVs (MSC-EVs) and their potent effects on extracellular matrix turnover, local cell recruitment, proliferation and angiogenesis is now well described. These positive outcomes have led to clinical trials assessing the safety of MSC-EVs for applications in wound healing and the treatment of cutaneous ulcers, as well as the emergence of multiple commercial MSC-EV sources marketed for topical application in cosmetic medicine. However, regenerative EV therapeutics remain in their infancy and pertinent questions regarding product standardisation, potency and the regulatory landscape surrounding the development of these promising nano-therapeutics must be addressed to ensure safe and effective clinical adoption. In this article we provide an overview of the emerging landscape of MSC-EVs in regenerative dermatology and cosmetic science, highlighting the underlying biological mechanisms pertinent to their application and providing a perspective on current safety considerations, regulation and future directions in the field.

Comparison of the structures and topologies of plasma extracted circulating nuclear and mitochondrial cell-free DNA

Introduction: The function, origin and structural features of circulating nuclear DNA (cir-nDNA) and mitochondrial DNA (cir-mtDNA) are poorly known, even though they have been investigated in numerous clinical studies, and are involved in a number of routine clinical applications. Based on our previous report disproving the conventional plasma isolation used for cirDNA analysis, this work enables a direct topological comparison of the circulating structures associated with nuclear DNA and mitochondrial cell-free DNA. Materials and methods: We used a Q-PCR and low-pass whole genome sequencing (LP-WGS) combination approach of cir-nDNA and cir-mtDNA, extracted using a procedure that eliminates platelet activation during the plasma isolation process to prevent mitochondria release in the extracellular milieu. Various physical procedures, such as filtration and differential centrifugation, were employed to infer their circulating structures. Results: DSP-S cir-mtDNA mean size profiles distributed on a slightly shorter range than SSP-S. SSP-S detected 40-fold more low-sized cir-mtDNA fragments (<90 bp/nt) and three-fold less long-sized fragments (>200 bp/nt) than DSP-S. The ratio of the fragment number below 90 bp over the fragment number above 200 bp was very homogenous among both DSP-S and SSP-S profiles, being 134-fold lower with DSP-S than with SSP-S. Cir-mtDNA and cir-nDNA DSP-S and SSP-S mean size profiles of healthy individuals ranged in different intervals with periodic sub-peaks only detectable with cir-nDNA. The very low amount of cir-mtDNA fragments of short size observed suggested that most of the cir-mtDNA is poorly fragmented and appearing longer than ∼1,000 bp, the readout limit of this LP-WGS method. Data suggested that cir-nDNA is, among DNA extracted in plasma, associated with ∼8.6% of large structures (apoptotic bodies, large extracellular vesicles (EVs), cell debris…), ∼27.7% in chromatin and small EVs and ∼63.7% mainly in oligo- and mono-nucleosomes. By contrast, cir-mtDNA appeared to be preponderantly (75.7%) associated with extracellular mitochondria, either in its free form or with large EVs; to a lesser extent, it was also associated with other structures: small EVs (∼18.4%), and exosomes or protein complexes (∼5.9%). Conclusion: This is the first study to directly compare the structural features of cir-nDNA and cir-mtDNA. The significant differences revealed between both are due to the DNA topological structure contained in the nucleus (chromatin) and in the mitochondria (plasmid) that determine their biological stability in blood. Although cir-nDNA and cir-mtDNA are principally associated with mono-nucleosomes and cell-free mitochondria, our study highlights the diversity of the circulating structures associated with cell-free DNA. They consequently have different pharmacokinetics as well as physiological functions. Thus, any accurate evaluation of their biological or diagnostic individual properties must relies on appropriate pre-analytics, and optimally on the isolation or enrichment of one category of their cirDNA associated structures.

Extracellular vesicles and their cells of origin: Open issues in autoimmune diseases

The conventional therapeutic approaches to treat autoimmune diseases through suppressing the immune system, such as steroidal and non-steroidal anti-inflammatory drugs, are not adequately practical. Moreover, these regimens are associated with considerable complications. Designing tolerogenic therapeutic strategies based on stem cells, immune cells, and their extracellular vesicles (EVs) seems to open a promising path to managing autoimmune diseases' vast burden. Mesenchymal stem/stromal cells (MSCs), dendritic cells, and regulatory T cells (Tregs) are the main cell types applied to restore a tolerogenic immune status; MSCs play a more beneficial role due to their amenable properties and extensive cross-talks with different immune cells. With existing concerns about the employment of cells, new cell-free therapeutic paradigms, such as EV-based therapies, are gaining attention in this field. Additionally, EVs' unique properties have made them to be known as smart immunomodulators and are considered as a potential substitute for cell therapy. This review provides an overview of the advantages and disadvantages of cell-based and EV-based methods for treating autoimmune diseases. The study also presents an outlook on the future of EVs to be implemented in clinics for autoimmune patients.

Extracellular vesicles: A dive into their role in the tumor microenvironment and cancer progression

Extracellular vesicles (EVs) encompass a diverse set of membrane-derived particles released from cells and are found in numerous biological matrices and the extracellular space. Specific classes of EVs include apoptotic bodies, exosomes, and microvesicles, which vary in their size, origin, membrane protein expression, and interior cargo. EVs provide a mechanism for shuttling cargo between cells, which can influence cell physiology by transporting proteins, DNA, and RNA. EVs are an abundant component of the tumor microenvironment (TME) and are proposed to drive tumor growth and progression by communicating between fibroblasts, macrophages, and tumor cells in the TME. The cargo, source, and type of EV influences the pro- or anti-tumoral role of these molecules. Therefore, robust EV isolation and characterization techniques are required to ensure accurate elucidation of their association with disease. Here, we summarize different EV subclasses, methods for EV isolation and characterization, and a selection of current clinical trials studying EVs. We also review key studies exploring the role and impact of EVs in the TME, including how EVs mediate intercellular communication, drive cancer progression, and remodel the TME.

Antimicrobial and Immunomodulatory Potential of Cow Colostrum Extracellular Vesicles (ColosEVs) in an Intestinal In Vitro Model

Extracellular Vesicles (EVs) are nano-sized double-lipid-membrane-bound structures, acting mainly as signalling mediators between distant cells and, in particular, modulating the immune response and inflammation of targeted cells. Milk and colostrum contain high amounts of EVs that could be exploited as alternative natural systems in antimicrobial fighting. The aim of this study is to evaluate cow colostrum-derived EVs (colosEVs) for their antimicrobial, anti-inflammatory and immunomodulating effects in vitro to assess their suitability as natural antimicrobial agents as a strategy to cope with the drug resistance problem. ColosEVs were evaluated on a model of neonatal calf diarrhoea caused by Escherichia coli infection, a livestock disease where antibiotic therapy often has poor results. Colostrum from Piedmontese cows was collected within 24 h of calving and colosEVs were immediately isolated. IPEC-J2 cell line was pre-treated with colosEVs for 48 h and then infected with EPEC/NTEC field strains for 2 h. Bacterial adherence and IPEC-J2 gene expression analysis (RT-qPCR) of CXCL8, DEFB1, DEFB4A, TLR4, TLR5, NFKB1, MYD88, CGAS, RIGI and STING were evaluated. The colosEVs pre-treatment significantly reduced the ability of EPEC/NTEC strains to adhere to cell surfaces (p = 0.006), suggesting a role of ColosEVs in modulating host−pathogen interactions. Moreover, our results showed a significant decrease in TLR5 (p < 0.05), CGAS (p < 0.05) and STING (p < 0.01) gene expression in cells that were pre-treated with ColosEVs and then infected, thus highlighting a potential antimicrobial activity of ColosEVs. This is the first preliminarily study investigating ColosEV immunomodulatory and anti-inflammatory effects on an in vitro model of neonatal calf diarrhoea, showing its potential as a therapeutic and prophylactic tool.

Extracellular Vesicles from Animal Milk: Great Potentialities and Critical Issues

Other than representing the main source of nutrition for newborn mammals, milk delivers a sophisticated signaling system from mother to child that promotes postnatal health. The bioactive components transferred through the milk intake are important for the development of the newborn immune system and include oligosaccharides, lactoferrin, lysozyme, α-La, and immunoglobulins. In the last 15 years, a pivotal role in this mother-to-child exchange has been attributed to extracellular vesicles (EVs). EVs are micro- and nanosized structures enclosed in a phospholipidic double-layer membrane that are produced by all cell types and released in the extracellular environment, reaching both close and distant cells. EVs mediate the intercellular cross-talk from the producing to the receiving cell through the transfer of molecules contained within them such as proteins, antigens, lipids, metabolites, RNAs, and DNA fragments. The complex cargo can induce a wide range of functional modulations in the recipient cell (i.e., anti-inflammatory, immunomodulating, angiogenetic, and pro-regenerative modulations) depending on the type of producing cells and the stimuli that these cells receive. EVs can be recovered from every biological fluid, including blood, urine, bronchoalveolar lavage fluid, saliva, bile, and milk, which is one of the most promising scalable vesicle sources. This review aimed to present the state-of-the-art of animal-milk-derived EV (mEV) studies due to the exponential growth of this field. A focus on the beneficial potentialities for human health and the issues of studying vesicles from milk, particularly for the analytical methodologies applied, is reported.

DEEP Surveillance of Brain Cancer Using Self-Functionalized 3D Nanoprobes for Noninvasive Liquid Biopsy

Brain cancers, one of the most fatal malignancies, require accurate diagnosis for guided therapeutic intervention. However, conventional methods for brain cancer prognosis (imaging and tissue biopsy) face challenges due to the complex nature and inaccessible anatomy of the brain. Therefore, deep analysis of brain cancer is necessary to (i) detect the presence of a malignant tumor, (ii) identify primary or secondary origin, and (iii) find where the tumor is housed. In order to provide a diagnostic technique with such exhaustive information here, we attempted a liquid biopsy-based deep surveillance of brain cancer using a very minimal amount of blood serum (5 μL) in real time. We hypothesize that holistic analysis of serum can act as a reliable source for deep brain cancer surveillance. To identify minute amounts of tumor-derived material in circulation, we synthesized an ultrasensitive 3D nanosensor, adopted SERS as a diagnostic methodology, and undertook a DEEP neural network-based brain cancer surveillance. Detection of primary and secondary tumor achieved 100% accuracy. Prediction of intracranial tumor location achieved 96% accuracy. This modality of using patient sera for deep surveillance is a promising noninvasive liquid biopsy tool with the potential to complement current brain cancer diagnostic methodologies.

Circulating tumor cells and extracellular vesicles as liquid biopsy markers in neuro-oncology: prospects and limitations

For many tumor entities, tumor biology and response to therapy are reflected by components that can be detected and captured in the blood stream. The so called “liquid biopsy” has been stratified over time into the analysis of circulating tumor cells (CTC), extracellular vesicles (EVs), and free circulating components such as cell-free nucleic acids or proteins. In neuro-oncology, two distinct areas need to be distinguished, intrinsic brain tumors and tumors metastatic to the brain. For intrinsic brain tumors, specifically glioblastoma, CTCs although present in low abundance, contain highly relevant, yet likely incomplete biological information for the whole tumor. For brain metastases, CTCs can have clinical relevance for patients especially with oligometastatic disease and brain metastasis in cancers like breast and lung cancer. EVs shed from the tumor cells and the tumor environment provide complementary information. Sensitive technologies have become available that are able to detect both, CTCs and EVs in the peripheral blood of patients with intrinsic and metastatic brain tumors despite the blood brain barrier. In reference to glioblastoma EVs, being shed by tumor cells and microenvironment and being more diffusible than CTCs may yield a more complete reflection of the whole tumor compared to low-abundance CTCs representing only a fraction of the multiclonal tumor heterogeneity. We here review the emerging aspects of CTCs and EVs as liquid biopsy biomarkers in neuro-oncology.